Optical lens assembly generating a plurality of near infrared light beams with different angles

ABSTRACT

An optical lens assembly is provided. The optical lens assembly includes first, second, third and fourth lens elements having refracting power arranged along an optical axis in a sequence from a light output side to a light input side. The first lens element is arranged to be a lens element in a fourth order from the light input side to the light output side. The second lens element is arranged to be a lens element in a third order from the light input side to the light output side. The third lens element is arranged to be a lens element in a second order from the light input side to the light output side. The fourth lens element is arranged to be a lens element in a first order from the light input side to the light output side.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Chinese applicationserial no. 201711071718.X, filed on Nov. 3, 2017. The entirety of theabove-mentioned patent application is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The invention provides an optical lens assembly.

2. Description of Related Art

As a critical part in portable electronic products with ever-changingspecifications, an optical lens assembly shows diversified developmentsfor not only capturing images or recording video, but also applicationfor a three-dimensional (3D) sensing technology with advancement oftechnology.

In the existing 3D sensing technology, multiple near infrared light beamemitting units generate a plurality of light beams respectively bymultiple collimating lenses to be projected to a front environment, soan image shown by near infrared light beams projected to the frontenvironment can be captured by a camera to create a 3D surroundingspace. More specifically, a light beam is generated from one nearinfrared light beam emitted by one near infrared light beam emittingunit passed through one corresponding collimating lens. In the existing3D sensing technology, the design of the collimating lenses is used todetect a larger-range environment. However, a manufacturing process forthe collimating lenses accompanied with the near infrared light beamemitting units has a high cost and a low yield rate. For instance,because each near infrared light beam emitting unit is extremely small,it is required to form the corresponding collimator lens by adopting awafer level optical lens manufacturing process. In such manufacturingprocess, the yield rate cannot be high and yet the manufacturing cost ishigher.

Therefore, designing a lens capable of cooperating with the nearinfrared light beam emitting units to generate light beams in differentangles while satisfying specifications for small volume, high yield rateand thermal stability is an issue to be addressed by persons skilled inthe art.

SUMMARY OF THE INVENTION

The invention is directed to an optical lens assembly for allowing astructured light generating unit having a plurality of light sources togenerate a plurality of light beams in different angles through theoptical lens assembly such that a cost of an transmitter lens in the 3Dsensing technology may be substantially reduced to reduce themanufacturing bottleneck.

An embodiment of the invention provides an optical lens assembly forgenerating a plurality of light beams from a plurality of near infraredlight beams emitted by a structured light generating unit having aplurality of light sources and passed through the optical lens assembly.A side facing the structured light generating unit having the lightsources is a light input side, and another side opposite thereto is alight output side. The optical lens assembly comprising a first lenselement, a second lens element, a third lens element and a fourth lenselement arranged along an optical axis in a sequence from the lightoutput side to the light input side. Each of the first lens element, thesecond lens element, the third lens element and the fourth lens elementcomprising a light output surface facing the light output side and alight input surface facing the light input side. The first lens elementis arranged to be a lens element having refracting power in a fourthorder from the light input side to the light output side. The secondlens element is arranged to be a lens element having refracting power ina third order from the light input side to the light output side. Thethird lens element is arranged to be a lens element having refractingpower in a second order from the light input side to the light outputside. The fourth lens element is arranged to be a lens element havingrefracting power in a first order from the light input side to the lightoutput side.

Based on the above, the optical lens assembly according to theembodiments of the invention can provide the following advantageouseffects. With an arrangement of the lens elements having refractingpower disposed between the light input side and the light output sidefor corresponding to the structured light generating unit having thelight sources, the cost of the transmitter lens in the 3D sensingtechnology may be substantially reduced to reduce the manufacturingbottleneck.

To make the above features and advantages of the disclosure morecomprehensible, several embodiments accompanied with drawings aredescribed in detail as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 1A is a schematic diagram illustrating an optical lens assembly ofthe invention applied as a 3D sensing transmitter lens.

FIG. 1B is a front view of an embodiment of a structured lightgenerating unit having a plurality of light sources in FIG. 1A.

FIG. 2 is a schematic view illustrating a surface structure of a lenselement.

FIG. 3 is a schematic view illustrating a concave and convex surfacestructure of a lens element and a ray focal point.

FIG. 4 is a schematic view illustrating a surface structure of a lenselement according to a first example.

FIG. 5 is a schematic view illustrating a surface structure of a lenselement according to a second example.

FIG. 6 is a schematic view illustrating a surface structure of a lenselement according to a third example.

FIG. 7 is a schematic view illustrating an optical lens assemblyaccording to a first embodiment of the invention.

FIG. 8A to FIG. 8D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the first embodiment.

FIG. 9 shows detailed optical data of the optical lens assemblyaccording to the first embodiment of the invention.

FIG. 10 shows aspheric parameters of the optical lens assembly accordingto the first embodiment of the invention.

FIG. 11 is a schematic view illustrating an optical lens assemblyaccording to a second embodiment of the invention.

FIG. 12A to FIG. 12D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the second embodiment.

FIG. 13 shows detailed optical data of the optical lens assemblyaccording to the second embodiment of the invention.

FIG. 14 shows aspheric parameters of the optical lens assembly accordingto the second embodiment of the invention.

FIG. 15 is a schematic view illustrating an optical lens assemblyaccording to a third embodiment of the invention.

FIG. 16A to FIG. 16D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the third embodiment.

FIG. 17 shows detailed optical data of the optical lens assemblyaccording to the third embodiment of the invention.

FIG. 18 shows aspheric parameters of the optical lens assembly accordingto the third embodiment of the invention.

FIG. 19 is a schematic view illustrating an optical lens assemblyaccording to a fourth embodiment of the invention.

FIG. 20A to FIG. 20D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the fourth embodiment.

FIG. 21 shows detailed optical data of the optical lens assemblyaccording to the fourth embodiment of the invention.

FIG. 22 shows aspheric parameters of the optical lens assembly accordingto the fourth embodiment of the invention.

FIG. 23 is a schematic view illustrating an optical lens assemblyaccording to a fifth embodiment of the invention.

FIG. 24A to FIG. 24D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the fifth embodiment.

FIG. 25 shows detailed optical data of the optical lens assemblyaccording to the fifth embodiment of the invention.

FIG. 26 shows aspheric parameters of the optical lens assembly accordingto the fifth embodiment of the invention.

FIG. 27 is a schematic view illustrating an optical lens assemblyaccording to a sixth embodiment of the invention.

FIG. 28A to FIG. 28D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the sixth embodiment.

FIG. 29 shows detailed optical data of the optical lens assemblyaccording to the sixth embodiment of the invention.

FIG. 30 shows aspheric parameters of the optical lens assembly accordingto the sixth embodiment of the invention.

FIG. 31 is a schematic view illustrating an optical lens assemblyaccording to a seventh embodiment of the invention.

FIG. 32A to FIG. 32D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the seventh embodiment.

FIG. 33 shows detailed optical data of the optical lens assemblyaccording to the seventh embodiment of the invention.

FIG. 34 shows aspheric parameters of the optical lens assembly accordingto the seventh embodiment of the invention.

FIG. 35 is a schematic view illustrating an optical lens assemblyaccording to an eighth embodiment of the invention.

FIG. 36A to FIG. 36D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the eighth embodiment.

FIG. 37 shows detailed optical data of the optical lens assemblyaccording to the eighth embodiment of the invention.

FIG. 38 shows aspheric parameters of the optical lens assembly accordingto the eighth embodiment of the invention.

FIG. 39 is a schematic view illustrating an optical lens assemblyaccording to a ninth embodiment of the invention.

FIG. 40A to FIG. 40D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the ninth embodiment.

FIG. 41 shows detailed optical data of the optical lens assemblyaccording to the ninth embodiment of the invention.

FIG. 42 shows aspheric parameters of the optical lens assembly accordingto the ninth embodiment of the invention.

FIG. 43 is a schematic view illustrating an optical lens assemblyaccording to a tenth embodiment of the invention.

FIG. 44A to FIG. 44D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the tenth embodiment.

FIG. 45 shows detailed optical data of the optical lens assemblyaccording to the tenth embodiment of the invention.

FIG. 46 shows aspheric parameters of the optical lens assembly accordingto the tenth embodiment of the invention.

FIG. 47 is a schematic view illustrating an optical lens assemblyaccording to an eleventh embodiment of the invention.

FIG. 48A to FIG. 48D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the eleventh embodiment.

FIG. 49 shows detailed optical data of the optical lens assemblyaccording to the eleventh embodiment of the invention.

FIG. 50 shows aspheric parameters of the optical lens assembly accordingto the eleventh embodiment of the invention.

FIG. 51 is a schematic view illustrating an optical lens assemblyaccording to a twelfth embodiment of the invention.

FIG. 52A to FIG. 52D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the twelfth embodiment.

FIG. 53 shows detailed optical data of the optical lens assemblyaccording to the twelfth embodiment of the invention.

FIG. 54 shows aspheric parameters of the optical lens assembly accordingto the twelfth embodiment of the invention.

FIG. 55 is a schematic view illustrating an optical lens assemblyaccording to a thirteenth embodiment of the invention.

FIG. 56A to FIG. 56D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the thirteenth embodiment.

FIG. 57 shows detailed optical data of the optical lens assemblyaccording to the thirteenth embodiment of the invention.

FIG. 58 shows aspheric parameters of the optical lens assembly accordingto the thirteenth embodiment of the invention.

FIG. 59 is a schematic view illustrating an optical lens assemblyaccording to a fourteenth embodiment of the invention.

FIG. 60A to FIG. 60D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the fourteenth embodiment.

FIG. 61 shows detailed optical data of the optical lens assemblyaccording to the fourteenth embodiment of the invention,

FIG. 62 shows aspheric parameters of the optical lens assembly accordingto the fourteenth embodiment of the invention.

FIG. 63 is a schematic view illustrating an optical lens assemblyaccording to a fifteenth embodiment of the invention.

FIG. 64A to FIG. 64D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the fifteenth embodiment.

FIG. 65 shows detailed optical data of the optical lens assemblyaccording to the fifteenth embodiment of the invention.

FIG. 66 shows aspheric parameters of the optical lens assembly accordingto the fifteenth embodiment of the invention.

FIG. 67 is a schematic view illustrating an optical lens assemblyaccording to a sixteenth embodiment of the invention.

FIG. 68A to FIG. 68D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the sixteenth embodiment.

FIG. 69 shows detailed optical data of the optical lens assemblyaccording to the sixteenth embodiment of the invention.

FIG. 70 shows aspheric parameters of the optical lens assembly accordingto the sixteenth embodiment of the invention.

FIG. 71 is a schematic view illustrating an optical lens assemblyaccording to a seventeenth embodiment of the invention.

FIG. 72A to FIG. 72D are graphs showing a longitudinal sphericalaberration and other aberrations of the optical lens assembly accordingto the seventeenth embodiment.

FIG. 73 shows detailed optical data of the optical lens assemblyaccording to the seventeenth embodiment of the invention.

FIG. 74 shows aspheric parameters of the optical lens assembly accordingto the seventeenth embodiment of the invention.

FIG. 75 and FIG. 76 show important parameters and values in relatedrelational expressions of the optical lens assembly according to thefirst to the sixth embodiments of the invention.

FIG. 77 and FIG. 78 show important parameters and values in relatedrelational expressions of the optical lens assembly according to theseventh to the twelfth embodiments of the invention.

FIG. 79 and FIG. 80 show important parameters and values in relatedrelational expressions of the optical lens assembly according to thethirteenth to the seventeenth embodiments of the invention.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numbers areused in the drawings and the description to refer to the same or likeparts.

Referring to FIG. 1A in which ray directions of a three-dimensional (3D)sensing transmitter lens 20 are illustrated, a plurality of nearinfrared light beams are emitted by a structured light generating unit15 having a plurality of light sources, and then pass through an opticallens assembly 10 according to embodiments of the invention to generate aplurality of light beams a, b and c, which are used to detect anenvironment in front of the lens. Here, types of the light beam a, b andc are not particularly limited. Travelling directions of the light beamsare illustrated by dotted lines. Also, the number of the light beams a,b and c are not limited to be exactly three but may be other numbers notequal to three and one. In FIG. 1A, the light beams a, b and c areillustrated as an example. Referring to FIG. 1B, in an embodiment, thestructured light generating unit 15 having the light sources includes aplurality of near infrared light beam light sources 15 a arranged in anarray. In other embodiments, the near infrared light beam light sources15 a may also be arranged in a ring arrangement or other arrangements,which are not particularly limited in the invention. The near infraredlight beam light sources 15 a may be infrared laser light sources. Lightemitting surfaces of the near infrared light beam light sources 15 aform a light emitting surface 100 a of the structured light generatingunit 15 having the light sources.

The following criteria for determining optical specifications in theembodiments of the invention is based on an assumption that a reversetracking of the ray direction is a parallel imaging ray passing throughthe optical lens assembly 10 from a light output side and focus on thelight emitting surface 100 a of the structured light generating unit 15having the light sources for imaging.

In the present specification, the description “a lens element havingpositive refracting power (or negative refracting power)” means that theparaxial refracting power of the lens element in Gaussian optics ispositive (or negative). The description “A light input surface (or lightoutput surface) surface of a lens element” only includes a specificregion of that surface of the lens element where imaging rays arecapable of passing through that region, namely the clear aperture of thesurface. The aforementioned imaging rays can be classified into twotypes, chief ray Lc and marginal ray Lm. Taking a lens element depictedin FIG. 2 as an example, I is an optical axis and the lens element isrotationally symmetric, where the optical axis I is the axis ofsymmetry. The region A of the lens element is defined as “a portion in avicinity of the optical axis”, and the region C of the lens element isdefined as “a portion in a vicinity of a periphery of the lens element”.Besides, the lens element may also have an extending portion E extendedradially and outwardly from the region C, namely the portion outside ofthe clear aperture of the lens element. The extending portion E isusually used for physically assembling the lens element into an opticalimaging lens system. Under normal circumstances, the imaging rays wouldnot pass through the extending portion E because those imaging rays onlypass through the clear aperture. The structures and shapes of theaforementioned extending portion E are only examples for technicalexplanation, the structures and shapes of lens elements should not belimited to these examples. Note that the extending portions of the lenselement surfaces depicted in the following embodiments are partiallyomitted. The following criteria are provided for determining the shapesand the portions of lens element surfaces set forth in the presentspecification. These criteria mainly determine the boundaries ofportions under various circumstances including the portion in a vicinityof the optical axis, the portion in a vicinity of a periphery of a lenselement surface, and other types of lens element surfaces such as thosehaving multiple portions.

1. FIG. 2 is a radial cross-sectional view of a lens element. Beforedetermining boundaries of those aforesaid portions, two referentialpoints should be defined first, central point and transition point. Thecentral point of a surface of a lens element is a point of intersectionof that surface and the optical axis. The transition point is a point ona surface of a lens element, where the tangent line of that point isperpendicular to the optical axis. Additionally, if multiple transitionpoints appear on one single surface, then these transition points aresequentially named along the radial direction of the surface withnumbers starting from the first transition point. For instance, thefirst transition point (closest one to the optical axis), the secondtransition point, and the Nth transition point (farthest one to theoptical axis within the scope of the clear aperture of the surface). Theportion of a surface of the lens element between the central point andthe first transition point is defined as the portion in a vicinity ofthe optical axis. The portion located radially outside of the Nthtransition point (but still within the scope of the clear aperture) isdefined as the portion in a vicinity of a periphery of the lens element.In some embodiments, there are other portions existing between theportion in a vicinity of the optical axis and the portion in a vicinityof a periphery of the lens element; the numbers of portions depend onthe numbers of the transition point(s). In addition, the radius of theclear aperture (or a so-called effective radius) of a surface is definedas the radial distance from the optical axis I to a point ofintersection of the marginal ray Lm and the surface of the lens element.

2. Referring to FIG. 3, determining the shape of a portion is convex orconcave depends on whether a collimated ray passing through that portionconverges or diverges. That is, while applying a collimated ray to aportion to be determined in terms of shape, the collimated ray passingthrough that portion will be bended and the ray itself or its extensionline will eventually meet the optical axis. The shape of that portioncan be determined by whether the ray or its extension line meets(intersects) the optical axis (focal point) at a light input side or alight output side. For instance, if the ray itself intersects theoptical axis at the light input side of the lens element after passingthrough a portion, i.e. the focal point of this ray is at the lightinput side (see point R in FIG. 3), the portion will be determined ashaving a convex shape. On the contrary, if the ray diverges afterpassing through a portion, the extension line of the ray intersects theoptical axis at the light output side of the lens element, i.e. thefocal point of the ray is at the light output side (see point M in FIG.3), that portion will be determined as having a concave shape.Therefore, referring to FIG. 3, the portion between the central pointand the first transition point has a convex shape, the portion locatedradially outside of the first transition point has a concave shape, andthe first transition point is the point where the portion having aconvex shape changes to the portion having a concave shape, namely theborder of two adjacent portions. Alternatively, there is another commonway for a person with ordinary skill in the art to tell whether aportion in a vicinity of the optical axis has a convex or concave shapeby referring to the sign of an “R” value, which is the (paraxial) radiusof curvature of a lens surface. The R value which is commonly used inconventional optical design software such as Zemax and CodeV. The Rvalue usually appears in the lens data sheet in the software. For thelight output surface, positive R means that the object-side surface isconvex, and negative R means that the light output surface is concave.Conversely, for the light input surface, positive R means that the lightinput surface is concave, and negative R means that the light inputsurface is convex. The result found by using this method should beconsistent as by using the other way mentioned above, which determinessurface shapes by referring to whether the focal point of a collimatedray is at the light output side or the light input side.

3. For none transition point cases, the portion in a vicinity of theoptical axis is defined as the portion between 0˜50% of the effectiveradius (radius of the clear aperture) of the surface, whereas theportion in a vicinity of a periphery of the lens element is defined asthe portion between 50˜100% of effective radius (radius of the clearaperture) of the surface.

Referring to the first example depicted in FIG. 4, only one transitionpoint, namely a first transition point, appears within the clearaperture of the light input surface of the lens element. Portion I is aportion in a vicinity of the optical axis, and portion II is a portionin a vicinity of a periphery of the lens element. The portion in avicinity of the optical axis is determined as having a concave surfacedue to the R value at the light input surface of the lens element ispositive. The shape of the portion in a vicinity of a periphery of thelens element is different from that of the radially inner adjacentportion, i.e. the shape of the portion in a vicinity of a periphery ofthe lens element is different from the shape of the portion in avicinity of the optical axis; the portion in a vicinity of a peripheryof the lens element has a convex shape.

Referring to the second example depicted in FIG. 5, a first transitionpoint and a second transition point exist on the light output surface(within the clear aperture) of a lens element. In which portion I is theportion in a vicinity of the optical axis, and portion III is theportion in a vicinity of a periphery of the lens element. The portion ina vicinity of the optical axis has a convex shape because the R value atthe light output surface of the lens element is positive. The portion ina vicinity of a periphery of the lens element (portion III) has a convexshape. What is more, there is another portion having a concave shapeexisting between the first and second transition point (portion II).

Referring to a third example depicted in FIG. 6, no transition pointexists on the light output surface of the lens element. In this case,the portion between 0˜50% of the effective radius (radius of the clearaperture) is determined as the portion in a vicinity of the opticalaxis, and the portion between 50˜100% of the effective radius isdetermined as the portion in a vicinity of a periphery of the lenselement. The portion in a vicinity of the optical axis of the lightoutput surface of the lens element is determined as having a convexshape due to its positive R value, and the portion in a vicinity of aperiphery of the lens element is determined as having a convex shape aswell.

FIG. 7 is a schematic view illustrating an optical lens assemblyaccording to a first embodiment of the invention, and FIG. 8A to FIG. 8Dare graphs showing a longitudinal spherical aberration and otheraberrations of the optical lens assembly according to the firstembodiment. With reference to FIG. 7, in the optical lens assembly 10according to the first embodiment of the invention, an aperture stop 2,a first lens element 3, a second lens element 4, a third lens element 5and a fourth lens element 6 are arranged in a sequence from the lightoutput side to the light input side along an optical axis I of theoptical lens assembly 10. When being emitted by the light emittingsurface 100 a of the structured light generating unit 15 having thelight sources, a plurality of near infrared light beams enter theoptical lens assembly 10 and sequentially pass through the fourth lenselement 6, the third lens element 5, the second lens element 4, thefirst lens element 3 and the aperture stop 2 to generate a plurality oflight beams to be outputted from the optical lens assembly 10. It isadded that, a side facing the structured light generating unit 15 havingthe light sources is the light input side, and another side oppositethereto is the light output side.

Further, in order to maintain a certain optical quality in a thermalenvironment for the optical lens assembly 10 according to theembodiments of the invention, the impact on output light beams caused bytemperature may be reduced by setting the first lens element 3 havingrefracting power closest to the aperture stop 2 to be made of a glasswith a refractive index greater than 1.8. The second lens element 4 tothe fourth lens element 6 are made of a plastic material, but materialsof the first lens element 3 to the fourth lens element 7 are not limitedthereto.

In the present embodiment, each of the first lens element 3, the secondlens element 4, the third lens element 5 and the fourth lens element 6of the optical lens assembly 10 has a light output surface 31, 41, 51,61 facing the light output side for allowing the near infrared lightbeams to pass through, and a light input surface 32, 42, 52, 62 facingthe light input side for allowing the near infrared light beams to passthrough.

The first lens element 3 is arranged to be a lens element havingrefracting power in a fourth order from the light input side to thelight output side. The first lens element 3 has positive refractingpower. The light output surface 31 of the first lens element 3 has aconvex portion 331 in a vicinity of the optical axis I and a convexportion 313 in a vicinity of a periphery of the first lens element 3.The light input surface 32 of the first lens element 3 has a concaveportion 322 in a vicinity of the optical axis I and a concave portion324 in a vicinity of a periphery of the first lens element 3. The lightoutput surface 31 and the light input surface 32 of the first lenselement 3 are aspheric surfaces.

The second lens element 4 is arranged to be a lens element havingrefracting power in a third order from the light input side to the lightoutput side. The second lens element has negative refracting power. Thelight output surface 41 of the second lens element 4 has a convexportion 411 in a vicinity of the optical axis I and a convex portion 413in a vicinity of a periphery of the second lens element 4. The lightinput surface 42 of the second lens element 4 has a concave portion 422in a vicinity of the optical axis I and a concave portion 424 in avicinity of a periphery of the second lens element 4. The light outputsurface 41 and the light input surface 42 of the second lens element 4are aspheric surfaces.

The third lens element 5 is arranged to be a lens element havingrefracting power in a second order from the light input side to thelight output side. The third lens element 5 has negative refractingpower. The light output surface 51 of the third lens element 5 has aconcave portion 512 in a vicinity of the optical axis I and a concaveportion 514 in a vicinity of a periphery of the third lens element 5.The light input surface 52 of the third lens element 5 has a concaveportion 522 in a vicinity of the optical axis I and a concave portion524 in a vicinity of a periphery of the third lens element 5. The lightoutput surface 51 and the light input surface 52 of the third lenselement 5 are aspheric surfaces.

The fourth lens element 6 is arranged to be a lens element havingrefracting power in a first order from the light input side to the lightoutput side. The fourth lens element 6 has positive refracting power.The light output surface 61 of the fourth lens element 6 has a concaveportion 612 in a vicinity of the optical axis I and a concave portion614 in a vicinity of a periphery of the fourth lens element 6. The lightinput surface 62 of the fourth lens element 6 has a convex portion 621in a vicinity of the optical axis I and a convex portion 623 in avicinity of a periphery of the fourth lens element 6. The light outputsurface 61 and the light input surface 62 of the fourth lens element 6are aspheric surfaces.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the first embodiment are shown in FIG. 9,in which the optical lens assembly 10 of the first embodiment has anoverall effective focal length (EFL) being 3.562 millimeter (mm), a halffield of view (HFOV) being 9.905°, an f-number (Fno) being 2.273, asystem length being 2.738 mm and a light circle radius being 0.603 mm.Here, the system length refers to a distance from the light inputsurface 31 of the first lens element 3 to the light emitting surface 100a along the optical axis I. The so-called “Fno” in the presentdisclosure refers to an f-number obtained by calculation according tothe reversibility principle of light with the aperture stop 2 regardedas an entrance pupil.

Further, in the present embodiment, all of the light output surfaces 31,41, 51 and 61 and the light input surfaces 32, 42, 52 and 62 of thefirst lens element 3, the second lens element 4, the third lens element5 and the fourth lens element 6 (8 surfaces in total) are asphericsurfaces. The light output surfaces 31, 41, 51 and 61 and the lightinput surfaces 32, 42, 52 and 62 are common even asphere surfaces. Theseaspheric surfaces are defined by the following formula.

$\begin{matrix}{{Z(Y)} = {{\frac{Y^{2}}{R}/\left( {1 + \sqrt{1 - {\left( {1 + K} \right)\frac{Y^{2}}{R^{2}}}}} \right)} + {\sum\limits_{i = 1}^{n}\;{a_{i} \times Y^{i}}}}} & (1)\end{matrix}$

-   -   Therein,    -   Y: a distance from a point on an aspheric curve to the optical        axis I;    -   Z: a depth of the aspheric surface (a perpendicular distance        between the point on the aspheric surface that is spaced from        the optical axis I by the distance Y and a tangent plane tangent        to a vertex of the aspheric surface on the optical axis I);    -   R: a radius of curvature of the surface of the lens element        close to the optical axis I;    -   K: a conic constant;    -   a_(i): an i^(th) aspheric coefficient;

The aspheric coefficients of the light output surface 31 of the firstlens element 3 to the light input surface 62 of the fourth lens element6 in Formula (1) are shown in FIG. 10. In FIG. 10, a field number “31”indicates that the respective row includes the aspheric coefficients ofthe light output surface 31 of the first lens element 3, and the sameapplies to the rest of fields.

In addition, relationship among the important parameters in the opticallens assembly 10 of the first embodiment is shown in FIG. 75 and FIG.76, where the unit for each parameter in FIG. 75 is millimeter (mm).

-   -   Therein,    -   T1 is a thickness of the first lens element 3 along the optical        axis I;    -   T2 is a thickness of the second lens element 4 along the optical        axis I;    -   T3 is a thickness of the third lens element 5 along the optical        axis I;    -   T4 is a thickness of the fourth lens element 6 along the optical        axis I;    -   G12 is an air gap from the first lens element 3 to the second        lens element 4 along the optical axis I;    -   G23 is an air gap from the second lens element 4 to the third        lens element 5 along the optical axis I;    -   G34 is an air gap from the third lens element 5 to the fourth        lens element 6 along the optical axis I;    -   AAG is a sum of air gaps among all of the lens elements having        refracting power of the optical lens assembly 10 along the        optical axis I;    -   ALT is a sum of thicknesses of all of the lens elements having        refracting power of the optical lens assembly 10 along the        optical axis I;    -   TL is a distance from the light output surface 31 of the first        lens element 3 to the light input surface 62 of the fourth lens        element 6 along the optical axis I;    -   TTL is a distance from the light output surface of a lens        element being a first piece having refracting power counted from        the light output side to the structured light generating having        the light sources unit along the optical axis I;    -   BFL is a distance from the light input surface 62 of the fourth        lens element 6 to the structured light generating unit having        the light sources along the optical axis I;    -   HFOV is a half field of view (marked by ω, as shown in FIG. 1A)        which is a maximum half light output angle of the optical lens        assembly 10;    -   Fno is the f-number, which refers to an f-number obtained by        calculating an effective aperture of the light beams emitted by        the optical lens assembly 10 according to the reversibility        principle of light, namely, the f-number obtained by calculation        according to the reversibility principle of light with the        aperture stop 2 regarded as the entrance pupil in the        embodiments of the invention;    -   LCR refers to a light circle radius (marked by LCR, as shown in        FIG. 1B), which is a radius of a smallest circumcircle of the        light emitting surface 100 a of the structured light generating        unit 15 having the light sources; and    -   EFL is the effective focal length of the optical lens assembly        10.    -   Besides, it is further defined that:    -   f1 is a focal length of the first lens element 3;    -   f2 is a focal length of the second lens element 4;    -   f3 is a focal length of the third lens element 5;    -   f4 is a focal length of the fourth lens element 6;    -   n1 is a refractive index of the first lens element 3;    -   n2 is a refractive index of the second lens element 4;    -   n3 is a refractive index of the third lens element 5;    -   n4 is a refractive index of the fourth lens element 6;    -   V1 is an Abbe number of the first lens element 3;    -   V2 is an Abbe number of the second lens element 4;    -   V3 is an Abbe number of the third lens element 5; and    -   V4 is an Abbe number of the fourth lens element 6.

With reference to FIG. 8A and FIG. 8B, the graph of FIG. 8A illustratesa longitudinal spherical aberration of the light emitting surface 100 awhen the pupil radius is 0.7836 mm and wavelengths are 930 nm, 940 nmand 950 nm in the first embodiment. The graphs of FIG. 8B and FIG. 8Crespectively illustrate a field curvature aberration in a sagittaldirection and a field curvature aberration in a tangential direction onthe lights emitting surface 100 a when wavelengths are 930 nm, 940 nmand 950 nm in the first embodiment. The graph of FIG. 8D illustrates adistortion aberration on the light emitting surface 100 a whenwavelengths are 930 nm, 940 nm and 950 nm in the first embodiment. Inthe graph of FIG. 8A which illustrates the longitudinal sphericalaberration in the first embodiment, the curve of each wavelength isclose to one another and approaches the center position, which indicatesthat the off-axis ray of each wavelength at different heights is focusedaround the imaging point. The skew margin of the curve of eachwavelength indicates that the imaging point deviation of the off-axisray at different heights is controlled within a range of ±10 μm. Hence,it is evident that the spherical aberration of the same wavelength canbe significantly improved according to the first embodiment. Inaddition, the curves of the three representative wavelengths are closeto one another, which indicate that the imaging positions of the rayswith different wavelengths are rather focused; therefore, the chromaticaberration can be significantly improved as well.

In the two graphs of the field curvature aberrations of FIG. 8B and FIG.8C, the focal length variation of the three representative wavelengthsin the entire field of view falls within a range of ±10 μm, andindicates that aberration of the optical lens assembly provided by thefirst embodiment can be effectively eliminated. In FIG. 8D, the graph ofdistortion aberration shows that the distortion aberration in the firstembodiment is maintained within a range of ±3.5%, which indicates thatthe distortion aberration in the first embodiment can comply with theimaging quality requirement of the optical lens assembly. Accordingly,compared to the existing optical lenses, with the system lengthshortened to approximately 2.738 mm, the first embodiment can stillprovide a favorable imaging quality. As a result, according to the firstembodiment, the length of the optical lens assembly can be shortenedwithout sacrificing the favorable optical properties.

FIG. 11 is a schematic view illustrating an optical lens assemblyaccording to a second embodiment of the invention, and FIG. 12A to FIG.12D are graphs showing a longitudinal spherical aberration and otheraberrations of the optical lens assembly according to the secondembodiment. With reference to FIG. 11, the second embodiment of theoptical lens assembly 10 is substantially similar to the firstembodiment, and the difference between the two is that, the opticaldata, the aspheric coefficients, and the parameters of the lens elements3, 4, 5 and 6 in these embodiments are different to some extent. Inaddition, the light input surface 32 of the first lens element 3 has aconvex portion 321 in a vicinity of the optical axis. The light outputsurface 41 of the second lens element 4 has a concave portion 412 in avicinity of the optical axis I. The light input surface 42 of the secondlens element 4 has a convex portion 421 in a vicinity of the opticalaxis I and a convex portion 423 in a vicinity of a periphery of thesecond lens element 4. The light output surface 51 of the third lenselement 5 has a convex portion 511 in a vicinity of the optical axis Iand a convex portion 513 in a vicinity of a periphery of the third lenselement 5. Further, an included angle between an emission direction of achief ray CF of the near infrared light beams emitted from the lightemitting surface 100 a of the structured light generating unit 15 havingthe light sources and a normal direction D of the light emitting surface100 a is less than 5°. It should be noted that, in order to show theview clearly, the reference numbers of the concave portions and theconvex portions identical to those in the first embodiment are omittedin FIG. 11.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the second embodiment of the optical lensassembly 10 are shown in FIG. 13, in which the optical lens assembly 10of the second embodiment has an overall effective focal length (EFL)being 2.785 millimeter (mm), a half field of view (HFOV) being 9.906°,an f-number (Fno) being 2.273, a system length being 2.845 mm and alight circle radius being 0.471 mm.

FIG. 14 shows the aspheric coefficients of the light output surface 31of the first lens element 3 to the light input surface 62 of the fourthlens element 6 in Formula (1) according to the second embodiment.

In addition, the relationship among the important parameters in theoptical lens assembly 10 of the second embodiment is shown in FIG. 75and FIG. 76.

In the graph of FIG. 12A which illustrates the longitudinal sphericalaberration when the pupil radius is 0.6128 mm according to the secondembodiment, the imaging point deviation of the off-axis ray at differentheights is controlled within a range of ±2.8 μm. In the two graphs ofthe field curvature aberrations of FIG. 12B and FIG. 12C, the focallength variation of the three representative wavelengths in the entirefield of view falls within a range of ±4.5 μm. In FIG. 12D, the graph ofdistortion aberration shows that the distortion aberration in the secondembodiment is maintained within a range of ±3.5%.

In view of the above description, it can be known that the half field ofview of the second embodiment is greater than the half field of view ofthe first embodiment. The longitudinal spherical aberration of thesecond embodiment is less than the longitudinal spherical aberration ofthe first embodiment. The field curvature of the second embodiment isless than the field curvature of the first embodiment.

FIG. 15 is a schematic view illustrating an optical lens assemblyaccording to a third embodiment of the invention, and FIG. 16A to FIG.16D are graphs showing a longitudinal spherical aberration and otheraberrations of the optical lens assembly according to the thirdembodiment. With reference to FIG. 15, the third embodiment of theoptical lens assembly 10 is substantially similar to the firstembodiment, and the difference between the two is that, the opticaldata, the aspheric coefficients, and the parameters of the lens elements3, 4, 5 and 6 in these embodiments are different to some extent. Inaddition, the light input surface 52 of the third lens element 5 has aconvex portion 521 in a vicinity of the optical axis I. Moreover, anincluded angle between a chief ray CF of the near infrared light beamsemitted from the structured light generating unit 15 having the lightsources and a normal direction D of the light emitting surface 100 a isless than 5°. It should be noted that, in order to show the viewclearly, the reference numbers of the concave portions and the convexportions identical to those in the first embodiment are omitted in FIG.15.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the third embodiment of the optical lensassembly 10 are shown in FIG. 17, in which the optical lens assembly 10of the third embodiment has an overall effective focal length (EFL)being 2.738 millimeter (mm), a half field of view (HFOV) being 9.900°,an f-number (Fno) being 2.273, a system length being 2.796 mm and alight circle radius being 0.496 mm.

FIG. 18 shows the aspheric coefficients of the light output surface 31of the first lens element 3 to the light input surface 62 of the fourthlens element 6 in Formula (1) according to the third embodiment.

In addition, the relationship among the important parameters in theoptical lens assembly 10 of the third embodiment is shown in FIG. 75 andFIG. 76.

In the graph of FIG. 16A which illustrates the longitudinal sphericalaberration when the pupil radius is 0.6023 mm according to the thirdembodiment, the imaging point deviation of the off-axis ray at differentheights is controlled within a range of ±3.0 μm. In the two graphs ofthe field curvature aberrations of FIG. 16B and FIG. 16C, the focallength variation of the three representative wavelengths in the entirefield of view falls within a range of ±4.5 μm. In FIG. 16D, the graph ofdistortion aberration shows that the distortion aberration in the thirdembodiment is maintained within a range of ±3.9%.

In view of the above description, it can be known that the longitudinalspherical aberration of the third embodiment is less than thelongitudinal spherical aberration of the first embodiment. The fieldcurvature of the third embodiment is less than the field curvature ofthe first embodiment.

FIG. 19 is a schematic view illustrating an optical lens assemblyaccording to a fourth embodiment of the invention, and FIG. 20A to FIG.20D are graphs showing a longitudinal spherical aberration and otheraberrations of the optical lens assembly according to the fourthembodiment. With reference to FIG. 19, the fourth embodiment of theoptical lens assembly 10 is substantially similar to the firstembodiment, and the difference between the two is that, the opticaldata, the aspheric coefficients, and the parameters of the lens elements3, 4, 5 and 6 in these embodiments are different to some extent. Inaddition, the light input surface 52 of the third lens element 5 has aconvex portion 521 in a vicinity of the optical axis I and a convexportion 523 in a vicinity of a periphery of the third lens element 5. Itshould be noted that, in order to show the view clearly, the referencenumbers of the concave portions and the convex portions identical tothose in the first embodiment are omitted in FIG. 19.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the fourth embodiment of the optical lensassembly 10 are shown in FIG. 21, in which the optical lens assembly 10of the fourth embodiment has an overall effective focal length (EFL)being 2.544 millimeter (mm), a half field of view (HFOV) being 9.900°,an f-number (Fno) being 2.273, a system length being 2.857 mm and alight circle radius being 0.467 mm.

FIG. 22 shows the aspheric coefficients of the light output surface 31of the first lens element 3 to the light input surface 62 of the fourthlens element 6 in Formula (1) according to the fourth embodiment.

In addition, the relationship among the important parameters in theoptical lens assembly 10 of the fourth embodiment is shown in FIG. 75and FIG. 76.

In the graph of FIG. 20A which illustrates the longitudinal sphericalaberration when the pupil radius is 0.5596 mm according to the fourthembodiment, the imaging point deviation of the off-axis ray at differentheights is controlled within a range of ±3.0 μm. In the two graphs ofthe field curvature aberrations of FIG. 20B and FIG. 20C, the focallength variation of the three representative wavelengths in the entirefield of view falls within a range of ±3.5 μm. In FIG. 20D, the graph ofdistortion aberration shows that the distortion aberration in the fourthembodiment is maintained within a range of ±5%.

In view of the above description, it can be known that the longitudinalspherical aberration of the fourth embodiment is less than thelongitudinal spherical aberration of the first embodiment. The fieldcurvature of the fourth embodiment is less than the field curvature ofthe first embodiment.

FIG. 23 is a schematic view illustrating an optical lens assemblyaccording to a fifth embodiment of the invention, and FIG. 24A to FIG.24D are graphs showing a longitudinal spherical aberration and otheraberrations of the optical lens assembly according to the fifthembodiment. With reference to FIG. 19, the fifth embodiment of theoptical lens assembly 10 is substantially similar to the firstembodiment, and the difference between the two is that, the opticaldata, the aspheric coefficients, and the parameters of the lens elements3, 4, 5 and 6 in these embodiments are different to some extent. Inaddition, the light input surface 52 of the third lens element 5 has aconvex portion 521 in a vicinity of the optical axis I. It should benoted that, in order to show the view clearly, the reference numbers ofthe concave portions and the convex portions identical to those in thefirst embodiment are omitted in FIG. 23.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the fifth embodiment of the optical lensassembly 10 are shown in FIG. 25, in which the optical lens assembly 10of the fifth embodiment has an overall effective focal length (EFL)being 2.616 millimeter (mm), a half field of view (HFOV) being 9.893°,an f-number (Fno) being 2.273, a system length being 2.940 mm and alight circle radius being 0.476 mm.

FIG. 26 shows the aspheric coefficients of the light output surface 31of the first lens element 3 to the light input surface 62 of the fourthlens element 6 in Formula (1) according to the fifth embodiment.

In addition, the relationship among the important parameters in theoptical lens assembly 10 of the fifth embodiment is shown in FIG. 75 andFIG. 76.

In the graph of FIG. 24A which illustrates the longitudinal sphericalaberration when the pupil radius is 0.5756 mm according to the fifthembodiment, the imaging point deviation of the off-axis ray at differentheights is controlled within a range of ±3.3 μm. In the two graphs ofthe field curvature aberrations of FIG. 24B and FIG. 24C, the focallength variation of the three representative wavelengths in the entirefield of view falls within a range of ±4.0 μm. In FIG. 24D, the graph ofdistortion aberration shows that the distortion aberration in the fifthembodiment is maintained within a range of ±4.5%.

In view of the above description, it can be known that the longitudinalspherical aberration of the fifth embodiment is less than thelongitudinal spherical aberration of the first embodiment. The fieldcurvature of the fifth embodiment is less than the field curvature ofthe first embodiment.

FIG. 27 is a schematic view illustrating an optical lens assemblyaccording to a sixth embodiment of the invention, and FIG. 28A to FIG.28D are graphs showing a longitudinal spherical aberration and otheraberrations of the optical lens assembly according to the sixthembodiment. With reference to FIG. 27, the sixth embodiment of theoptical lens assembly 10 is substantially similar to the firstembodiment, and the difference between the two is that, the opticaldata, the aspheric coefficients, and the parameters of the lens elements3, 4, 5 and 6 in these embodiments are different to some extent. Inaddition, the light output surface 41 of the second lens element 4 has aconcave portion 412 in a vicinity of the optical axis I. The light inputsurface 52 of the third lens element 5 has a convex portion 521 in avicinity of the optical axis I. The light output surface 61 of thefourth lens element 6 has a convex portion 613 in a vicinity of aperiphery of the fourth lens element 6. It should be noted that, inorder to show the view clearly, the reference numbers of the concaveportions and the convex portions identical to those in the firstembodiment are omitted in FIG. 27.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the sixth embodiment of the optical lensassembly 10 are shown in FIG. 29, in which the optical lens assembly 10of the sixth embodiment has an overall effective focal length (EFL)being 3.022 millimeter (mm), a half field of view (HFOV) being 9.895°,an f-number (Fno) being 2.273, a system length being 2.861 mm and alight circle radius being 0.587 mm.

FIG. 30 shows the aspheric coefficients of the light output surface 31of the first lens element 3 to the light input surface 62 of the fourthlens element 6 in Formula (1) according to the sixth embodiment.

In addition, the relationship among the important parameters in theoptical lens assembly 10 of the sixth embodiment is shown in FIG. 75 andFIG. 76.

In graph of FIG. 28A which illustrates the longitudinal sphericalaberration when the pupil radius is 0.6648 mm according to the sixthembodiment, the imaging point deviation of the off-axis ray at differentheights is controlled within a range of ±5.5 μm. In the two graphs ofthe field curvature aberrations of FIG. 28B and FIG. 28C, the focallength variation of the three representative wavelengths in the entirefield of view falls within a range of ±25 μm. In graph of FIG. 28D, thegraph of distortion aberration shows that the distortion aberration inthe sixth embodiment is maintained within a range of ±12%.

In view of the above description, it can be known that the longitudinalspherical aberration of the sixth embodiment is less than thelongitudinal spherical aberration of the first embodiment.

FIG. 31 is a schematic view illustrating an optical lens assemblyaccording to a seventh embodiment of the invention, and FIG. 32A to FIG.32D are graphs showing a longitudinal spherical aberration and otheraberrations of the optical lens assembly according to the seventhembodiment. With reference to FIG. 31, the seventh embodiment of theoptical lens assembly 10 is substantially similar to the firstembodiment, and the difference between the two is that, the opticaldata, the aspheric coefficients, and the parameters of the lens elements3, 4, 5 and 6 in these embodiments are different to some extent.Further, the second lens element 4 has positive refracting power. Thelight input surface 32 of the first lens element 3 is a sphericalsurface. It should be noted that, in order to show the view clearly, thereference numbers of the concave portions and the convex portionsidentical to those in the first embodiment are omitted in FIG. 31.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the seventh embodiment of the opticallens assembly 10 are shown in FIG. 33, in which the optical lensassembly 10 of the seventh embodiment has an overall effective focallength (EFL) being 2.696 millimeter (mm), a half field of view (HFOV)being 10.490°, an f-number (Fno) being 2.273, a system length being2.697 mm and a light circle radius being 0.500 mm.

FIG. 34 shows the aspheric coefficients of the light output surface 31of the first lens element 3 to the light input surface 62 of the fourthlens element 6 in Formula (1) according to the seventh embodiment.

In addition, relationship among the important parameters in the opticallens assembly 10 of the seventh embodiment is shown in FIG. 77 and FIG.78, where the unit for each parameter in FIG. 77 is millimeter (mm).

In the graph of FIG. 32A which illustrates the longitudinal sphericalaberration when the pupil radius is 0.5932 mm according to the seventhembodiment, the imaging point deviation of the off-axis ray at differentheights is controlled within a range of ±6.0 μm. In the two graphs ofthe field curvature aberrations of FIG. 32B and FIG. 32C, the focallength variation of the three representative wavelengths in the entirefield of view falls within a range of ±18 μm. In FIG. 32D, the graph ofdistortion aberration shows that the distortion aberration in theseventh embodiment is maintained within a range of ±0.045%.

In view of the above description, it can be known that the system lengthof the seventh embodiment is shorter than the system length of the firstembodiment. The half field of view of the seventh embodiment is greaterthan the half field of view of the first embodiment. The longitudinalspherical aberration of the seventh embodiment is less than thelongitudinal spherical aberration of the first embodiment.

FIG. 35 is a schematic view illustrating an optical lens assemblyaccording to an eighth embodiment of the invention, and FIG. 36A to FIG.36D are graphs showing a longitudinal spherical aberration and otheraberrations of the optical lens assembly according to the eighthembodiment. With reference to FIG. 35, the eighth embodiment of theoptical lens assembly 10 is substantially similar to the firstembodiment, and the difference between the two is that, the opticaldata, the aspheric coefficients, and the parameters of the lens elements3, 4, 5 and 6 in these embodiments are different to some extent. Inaddition, the light input surface 52 of the third lens element 5 has aconvex portion 521 in a vicinity of the optical axis I. It should benoted that, in order to show the view clearly, the reference numbers ofthe concave portions and the convex portions identical to those in thefirst embodiment are omitted in FIG. 35.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the eighth embodiment of the optical lensassembly 10 are shown in FIG. 37, in which the optical lens assembly 10of the eighth embodiment has an overall effective focal length (EFL)being 2.883 millimeter (mm), a half field of view (HFOV) being 9.898°,an f-number (Fno) being 2.273, a system length being 3.039 mm and alight circle radius being 0.525 mm.

FIG. 38 shows the aspheric coefficients of the light output surface 31of the first lens element 3 to the light input surface 62 of the fourthlens element 6 in Formula (1) according to the eighth embodiment.

In addition, the relationship among the important parameters in theoptical lens assembly 10 of the eighth embodiment is shown in FIG. 77and FIG. 78.

In the graph of FIG. 36A which illustrates the longitudinal sphericalaberration when the pupil radius is 0.6343 mm according to the eighthembodiment, the imaging point deviation of the off-axis ray at differentheights is controlled within a range of ±3 μm. In the two graphs of thefield curvature aberrations of FIG. 36B and FIG. 36C, the focal lengthvariation of the three representative wavelengths in the entire field ofview falls within a range of ±4.0 μm. In FIG. 36D, the graph ofdistortion aberration shows that the distortion aberration in the eighthembodiment is maintained within a range of ±4.5%.

In view of the above description, it can be known that the longitudinalspherical aberration of the eighth embodiment is less than thelongitudinal spherical aberration of the first embodiment. The fieldcurvature of the eighth embodiment is less than the field curvature ofthe first embodiment.

FIG. 39 is a schematic view illustrating an optical lens assemblyaccording to a ninth embodiment of the invention, and FIG. 40A to FIG.40D are graphs showing a longitudinal spherical aberration and otheraberrations of the optical lens assembly according to the ninthembodiment. With reference to FIG. 42, the ninth embodiment of theoptical lens assembly 10 is substantially similar to the firstembodiment, and the difference between the two is provided as follows.In the optical lens assembly 10 according to the ninth embodiment of theinvention, the aperture stop 2, a fifth lens element 7, the first lenselement 3, the second lens element 4, the third lens element 5 and thefourth lens element 6 are arranged in a sequence from the light outputside to the light input side along the optical axis I of the opticallens assembly 10. When a plurality of near infrared light beams areemitted by the light emitting surface 100 a of the structured lightgenerating unit 15 having the light sources, the near infrared lightbeams enter the optical lens assembly 10 and sequentially pass throughthe fourth lens element 6, the third lens element 5, the second lenselement 4, the first lens element 3, the fifth lens element 7 and theaperture stop 2 to generate a plurality of light beams to be outputtedfrom the optical lens assembly 10.

Each of the fifth lens element 7, the first lens element 3, the secondlens element 4, the third lens element 5 and the fourth lens element 6has a light output surface 71, 31, 41, 51, 61 facing the light outputside for allowing the near infrared light beams to pass through, and alight input surface 72, 32, 42, 52, 62 facing the light input side forallowing the near infrared light beams to pass through.

The fifth lens element 7 is disposed in front of the first lens element3. The fifth lens element 7 has positive refracting power. The lightoutput surface 71 of the fifth lens element 7 has a convex portion 711in a vicinity of the optical axis I and a convex portion 713 in avicinity of a periphery of the fifth lens element 7. The light inputsurface 72 of the fifth lens element 7 has a concave portion 722 in avicinity of the optical axis I and a concave portion 724 in a vicinityof a periphery of the fifth lens element 7. The light output surface 71and the light input surface 72 of the fifth lens element 7 are asphericsurfaces. The fifth lens element 7 is made of a plastic material.

The light input surface 32 of the first lens element 3 is a sphericalsurface.

The fourth lens element 6 has negative refracting power. The light inputsurface 62 of the fourth lens element 6 has a concave portion 622 in avicinity of the optical axis I. It should be noted that, in order toshow the view clearly, the reference numbers of the concave portions andthe convex portions identical to those in the first embodiment areomitted in FIG. 39.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the ninth embodiment are shown in FIG.41, in which the ninth embodiment has an overall effective focal length(EFL) being 3.930 mm, a half field of view (HFOV) being 7.694°, anf-number (Fno) being 2.273, a system length being 2.948 mm and a lightcircle radius being 0.500 mm. Here, the system length refers to adistance from the light output surface 71 of the fifth lens element 7 tothe light emitting surface 100 along the optical axis I.

Further, in the ninth embodiment, all of the light output surfaces 71,31, 41, 51 and 61 and the light input surfaces 72, 42, 52 and 62 of thefifth lens element 7, the first lens element 3, the second lens element4, the third lens element 5 and the fourth lens element 6 (9 surfaces intotal) are aspheric surfaces. These aspheric surfaces are defined byFormula (1), which is not repeated hereinafter. The asphericcoefficients of the light output surface 31 of the first lens element 3to the light input surface 72 of the fifth lens element 7 in Formula (1)are shown in FIG. 42. In FIG. 42, a field number “31” indicates that therespective row includes the aspheric coefficients of the light outputsurface 31 of the first lens element 3, and the same applies to the restof fields.

In addition, the relationship among the important parameters in theoptical lens assembly 10 of the ninth embodiment is shown in FIG. 77 andFIG. 78.

-   -   Parameter definition for the first lens element 3, the second        lens element 4, the third lens element 5 and the fourth lens        element 6 mentioned in the ninth embodiment are substantially        similar to the parameter definition mentioned in the first        embodiment, and their differences are:    -   T5 is a thickness of the fifth lens element 7 along the optical        axis I;    -   G51 is an air gap from the fifth lens element 7 to the first        lens element 3 along the optical axis I;    -   f5 is a focal length of the fifth lens element 7;    -   n5 is a refractive index of the fifth lens element 7; and    -   u5 is an Abbe number of the fifth lens element 7.

With reference to FIG. 40A and FIG. 40D, the graph of FIG. 40Aillustrates a longitudinal spherical aberration of the light emittingsurface 100 a when the pupil radius is 0.7836 mm and wavelengths are 930nm, 940 nm and 950 nm in the first embodiment. The graphs of FIG. 40Band FIG. 40C respectively illustrate a field curvature aberration in asagittal direction and a field curvature aberration in a tangentialdirection on the lights emitting surface 100 a when wavelengths are 930nm, 940 nm and 950 nm in the first embodiment. The graph of FIG. 40Dillustrates a distortion aberration on the light emitting surface 100 awhen wavelengths are 930 nm, 940 nm and 950 nm in the first embodiment.In the graph of FIG. 40A which illustrates the longitudinal sphericalaberration in the ninth embodiment, the curve of each wavelength isclose to one another and approaches the center position, which indicatesthat the off-axis ray of each wavelength at different heights is focusedaround the imaging point. The skew margin of the curve of eachwavelength indicates that the imaging point deviation of the off-axisray at different heights is controlled within a range of ±58 μm. Hence,it is evident that the spherical aberration of the same wavelength canbe significantly improved according to the ninth embodiment. Inaddition, the curves of the three representative wavelengths are closeto one another, which indicate that the imaging positions of the rayswith different wavelengths are rather focused; therefore, the chromaticaberration can be significantly improved as well.

In the two graphs of the field curvatures of FIG. 40B and FIG. 40C, thefocal length variation of the three representative wavelengths in theentire field of view falls within a range of ±6 μm, and indicates thatthe field curvature aberration of the optical system provided by theninth embodiment can be effectively eliminated. In FIG. 40D, the graphof distortion shows that the distortion aberration in the ninthembodiment is maintained within a range of ±8.0%, which indicates thatthe distortion aberration in the ninth embodiment can comply with theimaging quality requirement of the optical lens assembly. Accordingly,compared to the existing optical lens assembly, with the system lengthshortened to approximately 2.948 mm, the ninth embodiment can stillprovide a more preferable imaging quality. As a result, according to theninth embodiment, the length of the optical lens assembly can beshortened without sacrificing the favorable optical properties.

FIG. 43 is a schematic view illustrating an optical lens assemblyaccording to a tenth embodiment of the invention, and FIG. 44A to FIG.44D are graphs showing a longitudinal spherical aberration and otheraberrations of the optical lens assembly according to the tenthembodiment. With reference to FIG. 43, the tenth embodiment of theoptical lens assembly 10 is substantially similar to the ninthembodiment, and the difference between the two is that, the opticaldata, the aspheric coefficients, and the parameters of the lens elements3, 4, 5, 6 and 7 in these embodiments are different to some extent.Further, the second lens element 4 has positive refracting power. Thethird lens element 5 has positive refracting power. The light inputsurface 52 of the third lens element 5 has a convex portion 521 in avicinity of the optical axis I. The light output surface 61 of thefourth lens element 6 has a convex portion 611 in a vicinity of theoptical axis I and a convex portion 613 in a vicinity of a periphery ofthe fourth lens element 6. The light input surface 62 of the fourth lenselement 6 has a concave portion 624 in a vicinity of a periphery of thefourth lens element 6. Moreover, an included angle between a chief rayCF of the near infrared light beams emitted from the structured lightgenerating unit 15 having the light sources and a normal direction D ofthe light emitting surface 100 a is less than 5°. It should be notedthat, in order to show the view clearly, the reference numbers of theconcave portions and the convex portions identical to those in the ninthembodiment are omitted in FIG. 43.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the tenth embodiment of the optical lensassembly 10 are shown in FIG. 45, in which the optical lens assembly 10of the tenth embodiment has an overall effective focal length (EFL)being 2.825 millimeter (mm), a half field of view (HFOV) being 9.863°,an f-number (Fno) being 2.273, a system length being 3.881 mm and alight circle radius being 0.500 mm.

FIG. 46 shows the aspheric coefficients of the light output surface 71of the fifth lens element 7 to the light input surface 62 of the fourthlens element 6 in Formula (1) according to the tenth embodiment.

In addition, the relationship among the important parameters in theoptical lens assembly 10 of the tenth embodiment is shown in FIG. 77 andFIG. 78.

In the graph of FIG. 44A which illustrates the longitudinal sphericalaberration when the pupil radius is 0.6215 mm according to the tenthembodiment, the imaging point deviation of the off-axis ray at differentheights is controlled within a range of ±3.0 μm. In the two graphs ofthe field curvature aberrations of FIG. 44B and FIG. 44C, the focallength variation of the three representative wavelengths in the entirefield of view falls within a range of ±12 μm. In FIG. 44D, the graph ofdistortion aberration shows that the distortion aberration in the tenthembodiment is maintained within a range of ±1.4%.

In view of the above description, it can be known that the half field ofview of the tenth embodiment is greater than the half field of view ofthe ninth embodiment. The longitudinal spherical aberration of the tenthembodiment is less than the longitudinal spherical aberration of theninth embodiment. The field curvature of the tenth embodiment is lessthan the field curvature of the ninth embodiment. The distortionaberration of the tenth embodiment is less than the distortionaberration of the ninth embodiment.

FIG. 47 is a schematic view illustrating an optical lens assemblyaccording to an eleventh embodiment of the invention, and FIG. 48A toFIG. 48D are graphs showing a longitudinal spherical aberration andother aberrations of the optical lens assembly according to the eleventhembodiment. With reference to FIG. 47, the eleventh embodiment of theoptical lens assembly 10 is substantially similar to the ninthembodiment, and the difference between the two is that, the opticaldata, the aspheric coefficients, and the parameters of the lens elements3, 4, 5, 6 and 7 in these embodiments are different to some extent.Further, the fourth lens element 6 has positive refracting power. Thelight input surface 52 of the third lens element 5 has a convex portion521 in a vicinity of the optical axis I and a convex portion 523 in avicinity of a periphery of the third lens element 5. The light inputsurface 62 of the fourth lens element 6 has a convex portion 621 in avicinity of the optical axis I. Moreover, an included angle between achief ray CF of the near infrared light beams emitted from thestructured light generating unit 15 having the light sources and anormal direction D of the light emitting surface 100 a is less than 5°.It should be noted that, in order to show the view clearly, thereference numbers of the concave portions and the convex portionsidentical to those in the ninth embodiment are omitted in FIG. 47.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the eleventh embodiment of the opticallens assembly 10 are shown in FIG. 49, in which the optical lensassembly 10 of the eleventh embodiment has an overall effective focallength (EFL) being 2.672 millimeter (mm), a half field of view (HFOV)being 9.942°, an f-number (Fno) being 2.273, a system length being 2.814mm and a light circle radius being 0.500 mm.

FIG. 50 shows the aspheric coefficients of the light output surface 71of the fifth lens element 7 to the light input surface 62 of the fourthlens element 6 in Formula (1) according to the eleventh embodiment.

In addition, the relationship among the important parameters in theoptical lens assembly 10 of the eleventh embodiment is shown in FIG. 77and FIG. 78.

In the graph of FIG. 48A which illustrates the longitudinal sphericalaberration when the pupil radius is 0.5879 mm according to the eleventhembodiment, the imaging point deviation of the off-axis ray at differentheights is controlled within a range of ±1.6 μm. In the two graphs ofthe field curvature aberrations of FIG. 48B and FIG. 48C, the focallength variation of the three representative wavelengths in the entirefield of view falls within a range of ±3.0 μm. In FIG. 48D, the graph ofdistortion aberration shows that the distortion aberration in theeleventh embodiment is maintained within a range of ±6.0%.

In view of the above description, it can be known that the system lengthof the eleventh embodiment is shorter than the system length of theninth embodiment. The half field of view of the eleventh embodiment isgreater than the half field of view of the ninth embodiment. Thelongitudinal spherical aberration of the eleventh embodiment is lessthan the longitudinal spherical aberration of the ninth embodiment. Thefield curvature of the eleventh embodiment is less than the fieldcurvature of the ninth embodiment. The distortion aberration of theeleventh embodiment is less than the distortion aberration of the ninthembodiment.

FIG. 51 is a schematic view illustrating an optical lens assemblyaccording to a twelfth embodiment of the invention, and FIG. 52A to FIG.52D are graphs showing a longitudinal spherical aberration and otheraberrations of the optical lens assembly according to the twelfthembodiment. With reference to FIG. 51, the twelfth embodiment of theoptical lens assembly 10 is substantially similar to the ninthembodiment, and the difference between the two is that, the opticaldata, the aspheric coefficients, and the parameters of the lens elements3, 4, 5, 6 and 7 in these embodiments are different to some extent. Inaddition, the light input surface 62 of the fourth lens element 6 has aconvex portion 621 in a vicinity of the optical axis I. Moreover, anincluded angle between a chief ray CF of the near infrared light beamsemitted from the structured light generating unit 15 having the lightsources and a normal direction D of the light emitting surface 100 a isless than 5°. It should be noted that, in order to show the viewclearly, the reference numbers of the concave portions and the convexportions identical to those in the ninth embodiment are omitted in FIG.51.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the twelfth embodiment of the opticallens assembly 10 are shown in FIG. 53, in which the optical lensassembly 10 of the twelfth embodiment has an overall effective focallength (EFL) being 2.899 millimeter (mm), a half field of view (HFOV)being 9.943°, an f-number (Fno) being 2.273, a system length being 3.113mm and a light circle radius being 0.500 mm.

FIG. 54 shows the aspheric coefficients of the light output surface 71of the fifth lens element 7 to the light input surface 62 of the fourthlens element 6 in Formula (1) according to the twelfth embodiment.

In addition, the relationship among the important parameters in theoptical lens assembly 10 of the twelfth embodiment is shown in FIG. 77and FIG. 78.

In the graph of FIG. 52A which illustrates the longitudinal sphericalaberration when the pupil radius is 0.6377 mm according to the twelfthembodiment, the imaging point deviation of the off-axis ray at differentheights is controlled within a range of ±25 μm. In the two graphs of thefield curvature aberrations of FIG. 52B and FIG. 52C, the focal lengthvariation of the three representative wavelengths in the entire field ofview falls within a range of ±30.0 μm. In FIG. 52D, the graph ofdistortion aberration shows that the distortion aberration in thetwelfth embodiment is maintained within a range of ±1.4%.

In view of the above description, it can be known that the half field ofview of the twelfth embodiment is greater than the half field of view ofthe ninth embodiment. The longitudinal spherical aberration of thetwelfth embodiment is less than the longitudinal spherical aberration ofthe ninth embodiment. The field curvature of the twelfth embodiment isless than the field curvature of the ninth embodiment. The distortionaberration of the twelfth embodiment is less than the distortionaberration of the ninth embodiment.

FIG. 55 is a schematic view illustrating an optical lens assemblyaccording to a thirteenth embodiment of the invention, and FIG. 56A toFIG. 56D are graphs showing a longitudinal spherical aberration andother aberrations of the optical lens assembly according to thethirteenth embodiment. With reference to FIG. 55, the thirteenthembodiment of the optical lens assembly 10 is substantially similar tothe ninth embodiment, and the difference between the two is that, theoptical data, the aspheric coefficients, and the parameters of the lenselements 3, 4, 5, 6 and 7 in these embodiments are different to someextent. Further, the fifth lens element 7 has negative refracting power.The second lens element 4 has positive refracting power. The fourth lenselement 6 has positive refracting power. The light input surface 62 ofthe fourth lens element 6 has a convex portion 621 in a vicinity of theoptical axis I. Moreover, an included angle between a chief ray CF ofthe near infrared light beams emitted from the structured lightgenerating unit 15 having the light sources and a normal direction D ofthe light emitting surface 100 a is less than 5°. It should be notedthat, in order to show the view clearly, the reference numbers of theconcave portions and the convex portions identical to those in the ninthembodiment are omitted in FIG. 55.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the thirteenth embodiment of the opticallens assembly 10 are shown in FIG. 57, in which the optical lensassembly 10 of the thirteenth embodiment has an overall effective focallength (EFL) being 2.797 millimeter (mm), a half field of view (HFOV)being 9.939°, an f-number (Fno) being 2.273, a system length being 2.748mm and a light circle radius being 0.500 mm.

FIG. 58 shows the aspheric coefficients of the light output surface 71of the fifth lens element 7 to the light input surface 62 of the fourthlens element 6 in Formula (1) according to the thirteenth embodiment.

In addition, relationship among the important parameters in the opticallens assembly 10 of the thirteenth embodiment is shown in FIG. 79 andFIG. 80, where the unit for each parameter in FIG. 79 is millimeter(mm).

In the graph of FIG. 56A which illustrates the longitudinal sphericalaberration when the pupil radius is 0.6154 mm according to thethirteenth embodiment, the imaging point deviation of the off-axis rayat different heights is controlled within a range of ±2.5 μm. In the twographs of the field curvature aberrations of FIG. 56B and FIG. 56C, thefocal length variation of the three representative wavelengths in theentire field of view falls within a range of ±5.0 μm. In FIG. 56D, thegraph of distortion aberration shows that the distortion aberration inthe thirteenth embodiment is maintained within a range of ±2.0%.

FIG. 59 is a schematic view illustrating an optical lens assemblyaccording to a fourteenth embodiment of the invention, and FIG. 60A toFIG. 60D are graphs showing a longitudinal spherical aberration andother aberrations of the optical lens assembly according to thefourteenth embodiment. With reference to FIG. 59, the fourteenthembodiment of the optical lens assembly 10 is substantially similar tothe ninth embodiment, and the difference between the two is that, theoptical data, the aspheric coefficients, and the parameters of the lenselements 3, 4, 5, 6 and 7 in these embodiments are different to someextent. Further, the second lens element 4 has positive refractingpower. The light input surface 62 of the fourth lens element 6 has aconvex portion 621 in a vicinity of the optical axis I. Moreover, anincluded angle between a chief ray CF of the near infrared light beamsemitted from the structured light generating unit 15 having the lightsources and a normal direction D of the light emitting surface 100 a isless than 5°. It should be noted that, in order to show the viewclearly, the reference numbers of the concave portions and the convexportions identical to those in the ninth embodiment are omitted in FIG.59.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the fourteenth embodiment of the opticallens assembly 10 are shown in FIG. 61, in which the optical lensassembly 10 of the fourteenth embodiment has an overall effective focallength (EFL) being 2.765 millimeter (mm), a half field of view (HFOV)being 9.941°, an f-number (Fno) being 2.273, a system length being 3.157mm and a light circle radius being 0.500 mm.

FIG. 62 shows the aspheric coefficients of the light output surface 71of the fifth lens element 7 to the light input surface 62 of the fourthlens element 6 in Formula (1) according to the fourteenth embodiment.

In addition, the relationship among the important parameters in theoptical lens assembly 10 of the fourteenth embodiment is shown in FIG.79 and FIG. 80.

In the graph of FIG. 60A which illustrates the longitudinal sphericalaberration when the pupil radius is 0.6083 mm according to thefourteenth embodiment, the imaging point deviation of the off-axis rayat different heights is controlled within a range of ±1.5 μm. In the twographs of the field curvature aberrations of FIG. 60B and FIG. 60C, thefocal length variation of the three representative wavelengths in theentire field of view falls within a range of ±3.0 μm. In FIG. 60D, thegraph of distortion aberration shows that the distortion aberration inthe fourteenth embodiment is maintained within a range of ±2.5%.

In view of the above description, it can be known that the half field ofview of the fourteenth embodiment is greater than the half field of viewof the ninth embodiment. The longitudinal spherical aberration of thefourteenth embodiment is less than the longitudinal spherical aberrationof the ninth embodiment. The field curvature of the fourteenthembodiment is less than the field curvature of the ninth embodiment. Thedistortion aberration of the fourteenth embodiment is less than thedistortion aberration of the ninth embodiment.

FIG. 63 is a schematic view illustrating an optical lens assemblyaccording to a fifteenth embodiment of the invention, and FIG. 64A toFIG. 64D are graphs showing a longitudinal spherical aberration andother aberrations of the optical lens assembly according to thefifteenth embodiment. With reference to FIG. 63, the fifteenthembodiment of the optical lens assembly 10 is substantially similar tothe ninth embodiment, and the difference between the two is that, theoptical data, the aspheric coefficients, and the parameters of the lenselements 3, 4, 5, 6 and 7 in these embodiments are different to someextent. Further, the fourth lens element 6 has positive refractingpower. The light input surface 42 of the second lens element 4 has aconvex portion 423 in a vicinity of a periphery of the second lenselement 4. The light input surface 52 of the third lens element 5 has aconvex portion 521 in a vicinity of the optical axis I and a convexportion 523 in a vicinity of a periphery of the third lens element 5.The light output surface 61 of the fourth lens element 6 has a convexportion 611 in a vicinity of the optical axis I and a convex portion 613in a vicinity of a periphery of the fourth lens element 6. The lightinput surface 62 of the fourth lens element 6 has a concave portion 624in a vicinity of the optical axis I. Moreover, an included angle betweena chief ray CF of the near infrared light beams emitted from thestructured light generating unit 15 having the light sources and anormal direction D of the light emitting surface 100 a is less than 5°.It should be noted that, in order to show the view clearly, thereference numbers of the concave portions and the convex portionsidentical to those in the ninth embodiment are omitted in FIG. 63.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the fifteenth embodiment of the opticallens assembly 10 are shown in FIG. 65, in which the optical lensassembly 10 of the fifteenth embodiment has an overall effective focallength (EFL) being 2.754 millimeter (mm), a half field of view (HFOV)being 9.941°, an f-number (Fno) being 2.273, a system length being 3.433mm and a light circle radius being 0.500 mm.

FIG. 66 shows the aspheric coefficients of the light output surface 71of the fifth lens element 7 to the light input surface 62 of the fourthlens element 6 in Formula (1) according to the fifteenth embodiment.

In addition, the relationship among the important parameters in theoptical lens assembly 10 of the fifteenth embodiment is shown in FIG. 79and FIG. 80.

In the graph of FIG. 64A which illustrates the longitudinal sphericalaberration when the pupil radius is 0.6058 mm according to the fifteenthembodiment, the imaging point deviation of the off-axis ray at differentheights is controlled within a range of ±4.5 μm. In the two graphs ofthe field curvature aberrations of FIG. 64B and FIG. 64C, the focallength variation of the three representative wavelengths in the entirefield of view falls within a range of ±5.0 μm. In FIG. 64D, the graph ofdistortion aberration shows that the distortion aberration in the fifthembodiment is maintained within a range of ±3.0%.

In view of the above description, it can be known that the half field ofview of the fifteenth embodiment is greater than the half field of viewof the ninth embodiment. The longitudinal spherical aberration of thefifteenth embodiment is less than the longitudinal spherical aberrationof the ninth embodiment. The field curvature of the fifteenth embodimentis less than the field curvature of the ninth embodiment. The distortionaberration of the fifteenth embodiment is less than the distortionaberration of the ninth embodiment.

FIG. 67 is a schematic view illustrating an optical lens assemblyaccording to a sixteenth embodiment of the invention, and FIG. 68A toFIG. 68D are graphs showing a longitudinal spherical aberration andother aberrations of the optical lens assembly according to thesixteenth embodiment. With reference to FIG. 67, the sixteenthembodiment of the optical lens assembly 10 is substantially similar tothe ninth embodiment, and the difference between the two is that, theoptical data, the aspheric coefficients, and the parameters of the lenselements 3, 4, 5, 6 and 7 in these embodiments are different to someextent. Further, the fourth lens element 6 has positive refractingpower. The light input surface 32 of the first lens element 3 has aconvex portion 321 in a vicinity of the optical axis I and a convexportion 323 in a vicinity of a periphery of the first lens element 3.The light input surface 62 of the fourth lens element 6 has a convexportion 621 in a vicinity of the optical axis I. The first lens element3 is made of a plastic material. The fifth lens element 7 is made of aglass with refractive index greater than 1.8. Moreover, an includedangle between a chief ray CF of the near infrared light beams emittedfrom the structured light generating unit 15 having the light sourcesand a normal direction D of the light emitting surface 100 a is lessthan 5°. It should be noted that, in order to show the view clearly, thereference numbers of the concave portions and the convex portionsidentical to those in the ninth embodiment are omitted in FIG. 67.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the sixteenth embodiment of the opticallens assembly 10 are shown in FIG. 69, in which the optical lensassembly 10 of the sixteenth embodiment has an overall effective focallength (EFL) being 2.700 millimeter (mm), a half field of view (HFOV)being 10.491°, an f-number (Fno) being 2.273, a system length being3.110 mm and a light circle radius being 0.500 mm.

FIG. 70 shows the aspheric coefficients of the light output surface 71of the fifth lens element 7 to the light input surface 62 of the fourthlens element 6 in Formula (1) according to the sixteenth embodiment.

In addition, the relationship among the important parameters in theoptical lens assembly 10 of the sixteenth embodiment is shown in FIG. 79and FIG. 80.

In the graph of FIG. 68A which illustrates the longitudinal sphericalaberration when the pupil radius is 0.5939 mm according to the sixteenthembodiment, the imaging point deviation of the off-axis ray at differentheights is controlled within a range of ±4.5 μm. In the two graphs ofthe field curvature aberrations of FIG. 68B and FIG. 68C, the focallength variation of the three representative wavelengths in the entirefield of view falls within a range of ±25 μm. In FIG. 68D, the graph ofdistortion aberration shows that the distortion aberration in thesixteenth embodiment is maintained within a range of ±0.03%.

In view of the above description, it can be known that the half field ofview of the sixteenth embodiment is greater than the half field of viewof the ninth embodiment. The longitudinal spherical aberration of thesixteenth embodiment is less than the longitudinal spherical aberrationof the ninth embodiment. The field curvature of the sixteenth embodimentis less than the field curvature of the ninth embodiment. The distortionaberration of the sixteenth embodiment is less than the distortionaberration of the ninth embodiment.

FIG. 71 is a schematic view illustrating an optical lens assemblyaccording to a seventeenth embodiment of the invention, and FIG. 72A toFIG. 72D are graphs showing a longitudinal spherical aberration andother aberrations of the optical lens assembly according to theseventeenth embodiment. With reference to FIG. 71, the seventeenthembodiment of the optical lens assembly 10 is substantially similar tothe ninth embodiment, and the difference between the two is that, theoptical data, the aspheric coefficients, and the parameters of the lenselements 3, 4, 5, 6 and 7 in these embodiments are different to someextent. Further, the second lens element 4 has positive refractingpower. The third lens element 5 has positive refracting power. The lightinput surface 52 of the third lens element 5 has a convex portion 521 ina vicinity of the optical axis I and a convex portion 523 in a vicinityof a periphery of the third lens element 5. The light output surface 61of the fourth lens element 6 has a convex portion 611 in a vicinity ofthe optical axis I and a convex portion 613 in a vicinity of a peripheryof the fourth lens element 6. The light input surface 62 of the fourthlens element 6 has a concave portion 624 in a vicinity of a periphery ofthe fourth lens element 6. Moreover, an included angle between a chiefray CF of the near infrared light beams emitted from the structuredlight generating unit 15 having the light sources and a normal directionD of the light emitting surface 100 a is less than 5°. It should benoted that, in order to show the view clearly, the reference numbers ofthe concave portions and the convex portions identical to those in theninth embodiment are omitted in FIG. 71.

In the present embodiment, an included angle between an emissiondirection of a chief ray CF of the near infrared light beams emittedfrom the light emitting surface 100 a of the structured light generatingunit 15 having the light sources and a normal direction D of the lightemitting surface 100 a is less than 5°.

Other detailed optical data of the seventeenth embodiment of the opticallens assembly 10 are shown in FIG. 73, in which the optical lensassembly 10 of the seventeenth embodiment has an overall effective focallength (EFL) being 2.742 millimeter (mm), a half field of view (HFOV)being 9.937°, an f-number (Fno) being 2.273, a system length being 3.978mm and a light circle radius being 0.500 mm.

FIG. 74 shows the aspheric coefficients of the light output surface 71of the fifth lens element 7 to the light input surface 62 of the fourthlens element 6 in Formula (1) according to the seventeenth embodiment.

In addition, the relationship among the important parameters in theoptical lens assembly 10 of the seventeenth embodiment is shown in FIG.79 and FIG. 80.

In the graph of FIG. 72A which illustrates the longitudinal sphericalaberration when the pupil radius is 0.6032 mm according to theseventeenth embodiment, the imaging point deviation of the off-axis rayat different heights is controlled within a range of ±2.0 μm. In the twographs of the field curvature aberrations of FIG. 72B and FIG. 72C, thefocal length variation of the three representative wavelengths in theentire field of view falls within a range of ±4.5 μm. In FIG. 72D, thegraph of distortion aberration shows that the distortion aberration inthe seventeenth embodiment is maintained within a range of ±4%.

In view of the above description, it can be known that the half field ofview of the seventeenth embodiment is greater than the half field ofview of the ninth embodiment. The longitudinal spherical aberration ofthe seventeenth embodiment is less than the longitudinal sphericalaberration of the ninth embodiment. The field curvature of theseventeenth embodiment is less than the field curvature of the ninthembodiment. The distortion aberration of the seventeenth embodiment isless than the distortion aberration of the ninth embodiment.

At least one of the purposes of satisfying a condition EFL/ALT≤52.500aims to maintain the effective focal length and each optical parameterat appropriate values, so as to prevent the overall aberrationcorrection of the optical lens assembly 10 from being affected by anyoverly large parameter, or prevent the assembly from being affected orthe manufacturing difficulty from increased by any overly smallparameter. A more preferable limitation is 1.200≤EFL/ALT≤2.500.

For satisfying conditions (G23+G34+T4)/(T2+T3)≤3.800,(T1−G23+G34+T4)/(T2+T3)≤4.000, (LCR+T1)/(T3+T4)≤1.900,(AAG+BFL)/(T2+T4)≤1.800, LCR/T2≤2.500, TTL/(T2+T3)≤7.400,TTL/(T2+T3)≤7.400, TL/ALT≤1.900, (T1+G23)/(G12+G34)≤3.500,(T1+G23)/T2≤3.000, (T1+G34)/(G12+T2)≤2.500, (T1+G34)/T2≤3.500,(T1+T4)/(G12+T3)≤3.500, (T1+T4)/T2≤3.600, (T1+T4)/T3≤4.500,(G34+T4)/(T1+G12)≤2.500 and (G34+T4)/T2≤3.500, their more preferablelimitations are 1.200≤(G23+G34+T4)/(T2+T3)≤3.800,1.800≤(T1+G23+G34+T4)/(T2+T3)≤4.000, 0.600≤(LCR+T1)/(T3+T4)≤1.900,0.700≤(AAG+BFL)/(T2+T4)≤1.800, 0.900≤LCR/T2≤2.500,3.0005≤TTL/(T2+T3)≤7.400, 3.000≤TTL/(T2+T3)≤7.400, 1.100≤TL/ALT≤1.900,0.700≤(T1+G23)/(G12+G34)≤3.500, 1.700≤(T1+G23)/T2≤3.000,0.700≤(T1+G34)/(G12+T2)≤2.500, 1.300≤(T1+G34)/T2≤3.500,1.300≤(T1+T4)/(G12+T3)≤3.500, 1.700≤(T1+T4)/T2≤3.600,1.700≤(T1+T4)/T3≤4.500, 0.900≤(G34+T4)/(T1+G12)≤2.500 and1.200≤(G34+T4)/T2≤3.500. At least one of the purposes of satisfying theabove aims to maintain the thicknesses and the intervals of lenselements at appropriate values, so as to prevent the slimness of theoptical lens assembly 10 in whole from being affected by any overlylarge parameter, or prevent the assembly from being affected or themanufacturing difficulty from increased by any overly small parameter.

In addition, lens limitations may be further added by using anycombination relation of the parameters selected from the providedembodiments to implement the design for the optical lens assembly withthe same framework set forth in the embodiments of the invention.

Due to the unpredictability in an optical system design, with theframework set forth in the invention, the shortened lens length, theenlarged available aperture, the improved optical quality, or theimproved assembly yield can be achieved for the optical system of theinvention to improve the shortcomings of the related art ifaforementioned conditions are satisfied.

The aforementioned limitation relational expressions are provided in anexemplary sense and can be randomly and selectively combined and appliedto the embodiments of the invention in different manners; the inventionshould not be limited to the above examples. In implementation of theinvention, apart from the above-described relational expressions, it isalso possible to design additional detailed structures such as lensconcave and convex curvatures arrangements for the lens elements so asto enhance control of system property and/or resolution. For example, anadditional concave portion 311 in a vicinity of the optical axis I maybe selectively formed on the light output surface 31 the first lenselement 3. It should be noted that the above-described details can beoptionally combined and applied to the other embodiments of theinvention under the condition where they are not in conflict with oneanother.

To sum up, the optical lens assembly 10 described in the embodiments ofthe invention can provide at least one of the following advantagesand/or achieve at least one of the following effects.

1. The longitudinal spherical aberrations, the astigmatic aberrations,and the distortion aberrations provided in the embodiments of theinvention all comply with usage specifications. Moreover, all of theoff-axis rays of the three representative wavelengths 930 nm, 940 nm,and 950 nm at different heights are focused around the imaging point,and it can be observed that, in view of the skew margin of the curve foreach wavelength, all of the imaging point deviations of the off-axisrays at different heights are under control and have the capability ofsuppressing spherical aberrations, image aberrations, and distortion.With further examination upon the imaging quality data, inter-distancesbetween the three representative wavelengths 930 nm, 940 nm, and 950 nmare fairly close, indicating that rays with different wavelengths in theinvention can be well focused under different circumstances to providethe capability of suppressing dispersion.

2. With the first lens element 3 having positive refracting power, thelight output surface 31 of the first lens element 3 having the convexportion 313 in a vicinity of a periphery of the first lens element 3 andthe light input surface 32 of the first lens element 3 having theconcave portion 324 in a vicinity of a periphery of the first lenselement 3, the light output surface 41 of the second lens element 4having the convex portion 413 in a vicinity of a periphery of the secondlens element 4, a scattering degree of the light beams may beeffectively reduced.

3. With the light input surface 41 of the fourth lens element 4 havingthe convex portion 413 in a vicinity of a periphery of the fourth lenselement 4, the system length (TTL) may be effectively reduced by thefour lens elements under the premise that the spherical aberration andthe distortion are reduced.

4. With the limitation of TTL≤6 mm, the yield rate may be improved forapplication in larger portable electronic products. A more preferablelimitation is 4 mm or less for application in smaller portableelectronic products.

5. With HFOV≤20°, the distortion may be further reduced. If the includedangle between the chief ray CF of the near infrared light beams emittedfrom the structured light generating unit 15 having the light sourcesand a normal direction D of the light emitting surface 100 a is lessthan 5°, the scattering degree of the light beams may be reduced toenhance the 3D sensing effect.

6. If the conditions V1+V2+V3+V4≤141.0 or 2.550≤(n1+n2+n3+n4)−4 togetherwith limitations on the surface shapes are satisfied, the material withhigh refraction index may be adopted to prevent the output light beamsfrom being easily scattered with different distances, or to minimize thescattering degree and reduce the system length. A more preferablelimitations is V1+V2+V3+V4≤120.0 or 2.550≤(n1+n2+n3+n4)−4≤3.500.

7. If one of the lens elements in the optical lens assembly 10 of theinvention is made of the glass with the refractive index greater than1.8, the structured light generating unit 15 having the light sourcescan maintain a certain optical quality in the thermal environment toreduce the impact on the output light beams caused by temperature. Morepreferably, the glass material is used on the first lens element 3 orthe fifth lens element 7 having refracting power and closer the aperturestop 2.

All of the numerical ranges including the maximum and minimum values andthe values therebetween which are obtained from the combining proportionrelation of the optical parameters disclosed in each embodiment of theinvention are implementable.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims and their equivalents.

What is claimed is:
 1. An optical lens assembly, configured for aplurality of near infrared light beams emitted by a structured lightgenerating unit having a plurality of light sources to pass through, aside facing the structured light generating unit having the lightsources being a light input side, another side opposite thereto being alight output side, the optical lens assembly comprising a first lenselement, a second lens element, a third lens element and a fourth lenselement arranged along an optical axis in a sequence from the lightoutput side to the light input side, each of the first lens element, thesecond lens element, the third lens element and the fourth lens elementcomprising a light output surface facing the light output side and alight input surface facing the light input side, the optical lensassembly generating a plurality of light beams with different angles asthe plurality of near infrared light beams passed therethrough; whereinthe first lens element is arranged to be a lens element havingrefracting power in a fourth order from the light input side to thelight output side, the second lens element is arranged to be a lenselement having refracting power in a third order from the light inputside to the light output side, the third lens element is arranged to bea lens element having refracting power in a second order from the lightinput side to the light output side, and the fourth lens element isarranged to be a lens element having refracting power in a first orderfrom the light input side to the light output side.
 2. The optical lensassembly according to claim 1, wherein the optical lens assembly furthersatisfies:TTL≤6 mm;HFOV≤20°; and an included angle between an emission direction of a chiefray of the near infrared light beams emitted from a light emittingsurface of the structured light generating unit having the light sourcesand a normal direction of the light emitting surface being less than 5°,wherein TTL is a distance from the light output surface of a lenselement being a first piece having refracting power counted from thelight output side to the structured light generating unit having thelight sources along the optical axis, and HFOV is a half field of viewof the optical lens assembly.
 3. The optical lens assembly according toclaim 1, wherein the optical lens assembly further satisfies:V1+V2+V3+V4≤141 and 2.550≤(n1+n2+n3+n4)−4≤3.500, wherein V1 is an Abbenumber of the first lens element, V2 is an Abbe number of the secondlens element, V3 is an Abbe number of the third lens element, V4 is anAbbe number of the fourth lens element, n1 is a refractive index of thefirst lens element, n2 is a refractive index of the second lens element,n3 is a refractive index of the third lens element, and n4 is arefractive index of the fourth lens element.
 4. The optical lensassembly according to claim 1, wherein the optical lens assembly furthersatisfies: EFL/ALT≤2.500, wherein EFL is an effective focal length ofthe optical lens assembly, and ALT is a sum of thicknesses of all of thelens elements having refracting power of the optical lens assembly alongthe optical axis.
 5. The optical lens assembly according to claim 1,wherein the optical lens assembly further satisfies:(G23+G34+T4)/(T2+T3)≤3.800, wherein T2 is thickness of the second lenselement along the optical axis, T3 is a thickness of the third lenselement along the optical axis, T4 is a thickness of the fourth lenselement along the optical axis, G23 is an air gap from the second lenselement to the third lens element along the optical axis, and G34 is anair gap from the third lens element to the fourth lens element along theoptical axis.
 6. The optical lens assembly according to claim 1, whereinthe optical lens assembly further satisfies:(T1+G23+G34+T4)/(T2+T3)≤4.000, wherein T1 is a thickness of the firstlens element along the optical axis, T2 is a thickness of the secondlens element along the optical axis, T3 is a thickness of the third lenselement along the optical axis, T4 is a thickness of the fourth lenselement along the optical axis, G23 is an air gap from the second lenselement to the third lens element along the optical axis, and G34 is anair gap from the third lens element to the fourth lens element along theoptical axis.
 7. The optical lens assembly according to claim 1, whereinthe optical lens assembly further satisfies: (LCR+T1)/(T3+T4)≤1.900,wherein T1 is a thickness of the first lens element along the opticalaxis, T3 is a thickness of the third lens element along the opticalaxis, T4 is a thickness of the fourth lens element along the opticalaxis, and LCR is a radius of a smallest circumcircle of the lightemitting surface of the structured light generating unit having thelight sources.
 8. The optical lens assembly according to claim 1,wherein the optical lens assembly further satisfies:(AAG+BFL)/(T2+T4)≤1.800, wherein T2 is a thickness of the second lenselement along the optical axis, T4 is a thickness of the fourth lenselement along the optical axis, AAG is a sum of air gaps among all ofthe lens elements having refracting power of the optical lens assemblyalong the optical axis, and BFL is a distance from the light inputsurface of the fourth lens element to the structured light generatingunit having the light sources along the optical axis.
 9. The opticallens assembly according to claim 1, wherein the optical lens assemblyfurther satisfies: LCR/T2≤2.500, T2 is a thickness of the second lenselement along the optical axis, and LCR is a radius of a smallestcircumcircle of the light emitting surface of the structured lightgenerating unit having the light sources.
 10. The optical lens assemblyaccording to claim 1, wherein the optical lens assembly furthersatisfies: TTL/(T2+T3)≤7.400, wherein T2 is a thickness of the secondlens element along the optical axis, T3 is a thickness of the third lenselement along the optical axis, and TTL is a distance from the lightoutput surface of a lens element being a first piece having refractingpower counted from the light output side to the structured lightgenerating unit having the light sources along the optical axis.
 11. Theoptical lens assembly according to claim 1, wherein the optical lensassembly further satisfies: TL/ALT≤1.900, TL is a distance from thelight output surface of the first lens element to the light inputsurface of the fourth lens element, and ALT is a sum of thicknesses ofall of the lens elements having refracting power of the optical lensassembly along the optical axis.
 12. The optical lens assembly accordingto claim 1, wherein the optical lens assembly further satisfies:(T1+G23)/(G12+G34)≤3.500, wherein T1 is a thickness of the first lenselement along the optical axis, G12 is an air gap from the first lenselement to the second lens element along the optical axis, G23 is an airgap from the second lens element to the third lens element along theoptical axis, and G34 is an air gap from the third lens element to thefourth lens element along the optical axis.
 13. The optical lensassembly according to claim 1, wherein the optical lens assembly furthersatisfies: (T1+G23)/T2≤3.000, T1 is a thickness of the first lenselement along the optical axis, T2 is a thickness of the second lenselement along the optical axis, and G23 is an air gap from the secondlens element to the third lens element along the optical axis.
 14. Theoptical lens assembly according to claim 1, wherein the optical lensassembly further satisfies: (T1+G34)/(G12+T2)≤2.500, T1 is a thicknessof the first lens element along the optical axis, T2 is a thickness ofthe second lens element along the optical axis, G12 is an air gap fromthe first lens element to the second lens element along the opticalaxis, and G34 is an air gap from the third lens element to the fourthlens element along the optical axis.
 15. The optical lens assemblyaccording to claim 1, wherein the optical lens assembly furthersatisfies: (T1+G34)/T2≤3.500, wherein T1 is a thickness of the firstlens element along the optical axis, G34 is an air gap from the thirdlens element to the fourth lens element along the optical axis, and T2is a thickness of the second lens element along the optical axis. 16.The optical lens assembly according to claim 1, wherein the optical lensassembly further satisfies: (T1+T4)/(G12+T3)≤3.500, wherein T1 is athickness of the first lens element along the optical axis, T3 is athickness of the third lens element along the optical axis, T4 is athickness of the fourth lens element along the optical axis, and G12 isan air gap from the first lens element to the second lens element alongthe optical axis.
 17. The optical lens assembly according to claim 1,wherein the optical lens assembly further satisfies: (T1+T4)/T2≤3.600,wherein T1 is a thickness of the first lens element along the opticalaxis, T2 is a thickness of the second lens element along the opticalaxis, and T4 is a thickness of the fourth lens element along the opticalaxis.
 18. The optical lens assembly according to claim 1, wherein theoptical lens assembly further satisfies: (T1+T4)/T3≤4.500, wherein T1 isa thickness of the first lens element along the optical axis, T3 is athickness of the third lens element along the optical axis, and T4 is athickness of the fourth lens element along the optical axis.
 19. Theoptical lens assembly according to claim 1, wherein the optical lensassembly further satisfies: (G34+T4)/(T1+G12)≤2.500, wherein T1 is athickness of the first lens element along the optical axis, T4 is athickness of the fourth lens element along the optical axis, G12 is anair gap from the first lens element to the second lens element along theoptical axis, and G34 is an air gap from the third lens element to thefourth lens element along the optical axis.
 20. The optical lensassembly according to claim 1, wherein the optical lens assembly furthersatisfies: (G34+T4)/T2≤3.500, wherein T2 is a thickness of the secondlens element along the optical axis, T4 is a thickness of the fourthlens element along the optical axis, and G34 is an air gap from thethird lens element to the fourth lens element along the optical axis.